order to investigate the local conditions in 
the states Rio Grande do Norte, Parahyba» 
Pernambuco, Alagoas, Sergipe and Bahia, 
known as centres of intestinal schistosoma- 
tosis. The commission, composed of Drs. 
ADOLPHO LUTZ and OSWINO PENNA 
and two laboratory servants, found cases in 
all these states, especially in Pernambuco 
and Sergipe where they remained longer. 
They verified that Planorbis olivaceus is li- 
mited to the states Bahia and Sergipe ; more 
to the north the intermediary host is eviden- 
tly a smaller species, described as Pl. centi- 
metralis by LUTZ in his monograph of the 
South American Planorbis, published in the 
Memorias do Instituto Oswaldo Cruz, V. 
X, F. I, 1918. Quite to the north of the zone, 
crossed by the commission, appeared ano- 
ther species, Plonorbis guadaloupensis SO- 
WERBY which is the intermediate host of 
Sch. M. in Venezuela and probably also in 
all the Antilles where it exists. Of the last 
two species no infected specimens were 
found which, in the case of centimetralis, was 
probably due to the unfavourable season. I 
obtained the experimental infection of spe- 
mens belonging to Pl. guadaloupensis, recei- 
ved by the kindness of Mr. FABRICIO 
CALDAS DE OLIVEIRA in Maranhão. The 
infection of centimetralis has not yet been 
completed, though penetra tion of the mtraci- 
dia was observed on several occasions. Spon- 
taneous infection of Pl. olivaceus was obser- 
ved once in Sergipe and three times in the 
state Bahia. 
Later informations induce me to include 
Minas Geraes among the states infected with 
Sch. M. I learnt from Dr. HENRIQUE VIL- 
LELA that Dr. ABEL TAVARES observed 
severals patients in Bello Horizonte, voiding 
eggs of Sch. M. and probably infected in 
that region. Dr. PENNA also saw a case 
coming from the zone of the river Pomba in 
Minas. 
This agrees with anterior observations 
of LUTZ showing the occurrence of PJ. cen- 
timeiralis in Retiro near Juiz de Fora (Minas). 
Recent observations made by CHAGAS in- 
113 
dicate that Sch. M. also occurs in the Acre 
territory; thus actually all the states north of 
Rio may be considered as infected. 
I conclude this chapter with a recapitu- 
lation of the most important dates: 
1851 Discovery of Distoma haematobium 
in Egypt by BILHARZ. 
1858 WEINLAND proposes the genus 
Schistosomum. 
1864 HARLEY calls Distoma capense the 
South African blood flukes ha- 
ving eggs with terminal spines. 
1874 SONSINO discovers the Sch. cras- 
sum in cattle but fails to find the 
intermediary host of the human 
species, 
1876 COBBOLD fails to find the inter- 
mediary host. 
1888 ALLAN indicates infection through 
bathing (also BROOK in 1897). 
1892-1903 Imported cases of Sch, haema- 
tobium observed in the United 
States and in Panama. 
1902-1903 MANSON, LETULLE, GON- 
CALEZ-MARTINEZ and others 
begin to observe eggs with ter- 
minal spine in the stools of pa- 
tients infected in the Antilles. 
1905 BLUMGART in New-York obser- 
ves eggs with lateral spine in 
the stools of a person having 
spent 7 years in Brazil. 
1907 SAMBON introduces the name: 
Schistosomum Mansoni. 
1908 First communication of M. PIRAJÁ 
on the occurrence of Sch. M. in 
Bahia. 
1911 First communication of FLU on 
Sch. M. in Dutch Guiana. 
1911-1913 Discovery of Sch. japon. and 
its biology. 
1915 The LEIPER commission studies 
the evolution of human blood 
flukes. 
1916 LUTZ studies the evolution of Sch. 
M. in the brazilian Planorbis 
olivaceus. 
